Tanner Bolt's wife, Betsy Bolt, is a PR genius. In the book, she's the one cleaning up Nick's messes, and she's the one pelting him (with jelly beans, actually) before his Sharon Schieber interview.
Jacqueline Collings is the mother of Desi, and the two actually live together in the novel. While Desi has nothing but love for Amy, Jacqueline shows a strong dislike and opposition.
Hilary Handy, Amy's best friend from high school, is also missing. She's a small character, but she's crucial in demonstrating just how insane Amy actually is. Amy accused Hilary of stalking her, trying to become her, and even pushing her down a flight of stairs.